From bbc6fac387f09e46a372e4aadbc935cba5a6b463 Mon Sep 17 00:00:00 2001 From: Scott Wood Date: Mon, 27 Aug 2007 13:46:38 -0500 Subject: [POWERPC] bootwrapper: Add fsl_get_immr() and 8xx/pq2 clock functions. fsl_get_immr() uses /soc/ranges to determine the immr. mpc885_get_clock() transforms a crystal frequency into a system frequency according to the PLL register settings. pq2_get_clocks() does the same as the above for the PowerQUICC II, except that it produces several different clocks. The mpc8xx/pq2 set_clocks() functions modify common properties in the device tree based on the given clock data. The mpc885/pq2 fixup_clocks() functions call get_clocks(), and pass the results to set_clocks(). Signed-off-by: Scott Wood Acked-by: David Gibson Signed-off-by: Kumar Gala --- arch/powerpc/boot/mpc8xx.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 arch/powerpc/boot/mpc8xx.c (limited to 'arch/powerpc/boot/mpc8xx.c') diff --git a/arch/powerpc/boot/mpc8xx.c b/arch/powerpc/boot/mpc8xx.c new file mode 100644 index 00000000000..add55a7f184 --- /dev/null +++ b/arch/powerpc/boot/mpc8xx.c @@ -0,0 +1,82 @@ +/* + * MPC8xx support functions + * + * Author: Scott Wood + * + * Copyright (c) 2007 Freescale Semiconductor, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include "ops.h" +#include "types.h" +#include "fsl-soc.h" +#include "mpc8xx.h" +#include "stdio.h" +#include "io.h" + +#define MPC8XX_PLPRCR (0x284/4) /* PLL and Reset Control Register */ + +/* Return system clock from crystal frequency */ +u32 mpc885_get_clock(u32 crystal) +{ + u32 *immr; + u32 plprcr; + int mfi, mfn, mfd, pdf, div; + u32 ret; + + immr = fsl_get_immr(); + if (!immr) { + printf("mpc885_get_clock: Couldn't get IMMR base.\r\n"); + return 0; + } + + plprcr = in_be32(&immr[MPC8XX_PLPRCR]); + + mfi = (plprcr >> 16) & 15; + if (mfi < 5) { + printf("Warning: PLPRCR[MFI] value of %d out-of-bounds\r\n", + mfi); + mfi = 5; + } + + pdf = (plprcr >> 1) & 0xf; + div = (plprcr >> 20) & 3; + mfd = (plprcr >> 22) & 0x1f; + mfn = (plprcr >> 27) & 0x1f; + + ret = crystal * mfi; + + if (mfn != 0) + ret += crystal * mfn / (mfd + 1); + + return ret / (pdf + 1); +} + +/* Set common device tree fields based on the given clock frequencies. */ +void mpc8xx_set_clocks(u32 sysclk) +{ + void *node; + + dt_fixup_cpu_clocks(sysclk, sysclk / 16, sysclk); + + node = finddevice("/soc/cpm"); + if (node) + setprop(node, "clock-frequency", &sysclk, 4); + + node = finddevice("/soc/cpm/brg"); + if (node) + setprop(node, "clock-frequency", &sysclk, 4); +} + +int mpc885_fixup_clocks(u32 crystal) +{ + u32 sysclk = mpc885_get_clock(crystal); + if (!sysclk) + return 0; + + mpc8xx_set_clocks(sysclk); + return 1; +} -- cgit v1.2.3